A biosensor is a measuring apparatus for investigating properties of a material using functions of an organism. Since the biosensor uses a biomaterial as a detection element, sensitivity and reaction specificity are good. Accordingly, the biosensor is widely used in various fields such as clinical chemistry assay of medical/medicine fields, process measurement of bio industries, environment measurement, stability estimation of chemicals, and so on, and its range is being continuously enlarged. In particular, in a medicine diagnosis field, the biosensors are widely used to analyze a sample including a bio-sample. The biosensors are divided into enzyme assay biosensors and immunoassay biosensors according to the kind of detecting element, and into optical biosensors and electrochemical biosensors according to a method of quantitatively analyzing a target material within a bio-sample.
The enzyme assay biosensors are designed to use a specific reaction between an enzyme and a substrate and a specific reaction between an enzyme and an enzyme inhibitor, and the immunoassay biosensors are designed to use a specific reaction between an antigen and an antibody.
The optical biosensors are widely used to measure a concentration of a target material by measuring transmittance, absorbance, or alteration in wavelength. The optical biosensors have an advantage in that, since reaction mechanisms of various materials to be analyzed have already been known and measurement is made after a reaction takes place for a sufficient time, a deviation in measurement time is low. In contrast, the optical biosensors have a disadvantage in that they require a longer measurement time and a greater quantity of samples than the electrochemical biosensors. Further, the optical biosensors have other disadvantages in that measured results are influenced by turbidity of a sample, and it is difficult to miniaturize an optical unit.
The electrochemical biosensors are used to measure a concentration of a target material by measuring an electric signal obtained from a reaction. The electrochemical biosensors have advantages in that it is possible to amplify a signal using a very small quantity of sample, they are easy to miniaturize, it is possible to stably obtain a measured signal, and they can be easily combined with a telecommunication instrument. However, the electrochemical biosensors have disadvantages in that an electrode manufacturing process is additionally required, the cost of production is high, and a measured signal is very sensitive to response time.
Meanwhile, the conventional biosensor generally has a planar strip structure. A user needs to insert the bio sensor having a planar strip structure into a narrow slit of a detector, for example, when blood sugar is measured using the biosensor. However, for example, since many diabetic and elderly patients have poor vision, it is difficult to insert the biosensor having a planar strip structure into the narrow slit. In addition, when the biosensor is removed from the detector after measurement of the blood sugar, the user grips around a portion of the biosensor stained with the blood and extracts and wastes the biosensor. At this time, since the user's finger is likely to be stained with blood, the user may feel uncomfortable. In addition, the conventional strip type biosensor may be easily contaminated when the biosensor is inserted into the detector by the user.